A method for online estimation of the state of health of lithium-ion batteries

Abstract

The invention relates to an online estimation method of health status of a lithium ion battery. By using the online estimation method of the health status of the lithium ion battery, direct current internal resistance, the maximum discharge power and residual capacity of the lithium ion battery, which can reflect the health status, are finally obtained by analyzing and processing status data of charging voltage, balance electromotive potential, a charging current, charging time and the like of the lithium ion battery under operating conditions of the lithium ion battery. According to the online estimation method of the health status of the lithium ion battery, three indexes of the residual capacity, the direct current resistance and the maximum available power of the lithium ion battery during the ageing process are used to reflect the health status of the lithium ion battery. Compared with a traditional single parameter estimation method, the online estimation method of the health status of the lithium ion battery can enable a user to intuitively know the health status of the lithium ion battery, facilitates improvement of charge state estimation accuracy of the lithium ion battery, accurately judges the residual capacity of the lithium ion battery, and thereby accurately predicts endurance mileage of an electric car. Additionally, the user can timely replace the lithium ion battery poor in health condition, and guarantees performance of the electric car by using the online estimation method of the health status of the lithium ion battery.

Description

technical field [0001] The invention relates to a battery monitoring technology, in particular to an online estimation method for the health state of a lithium ion battery. Background technique [0002] With the continuous acceleration of the world's industrialization process, non-renewable energy sources such as coal and oil are consumed in large quantities and become increasingly exhausted. The global oil reserves will be exhausted in 40 years according to the current development requirements. Accounting for 60% of the total demand. For this reason, the development of new energy vehicles has become the general trend. [0003] The power battery is the core of the new energy vehicle as the electric vehicle, and the battery management system (BMS), as an important part of the electric vehicle supervision battery, has not yet matured. The battery health status estimation is the weak link of the current research and has become the current battery management system. The bigges...

AI Technical Summary

Problems solved by technology

[0005] The invention aims at the problem that the health status of the battery is difficult to detect during use, and proposes an online estimation method for the health status of the lithium-ion battery, which can be based on the charging voltage, balance electromotive force, charging current and charging time of the battery under the battery working condition. Data, and analyze and process these data, and finally can obtain the DC internal resistance, maximum discharge power and remaining capacity of the battery, which is the state of health of the battery

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